[lwp]添加select系统调用

components/dfs/src/select.c

@@ -28,6 +28,19 @@
 #include <dfs_poll.h>
 #include <dfs_select.h>
 
+static void fdzero(fd_set *set, int nfds)
+{
+    fd_mask *m;
+    int n;
+
+    m = (fd_mask*)set;
+    for (n = 0; n < nfds; n += sizeof(fd_mask))
+    {
+        rt_memset(m, 0, sizeof(fd_mask));
+        m ++;
+    }
+}
+
 int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout)
 {
     int fd;
@@ -113,17 +126,17 @@ int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struc
     /* Now set up the return values */
     if (readfds)
     {
-        memset(readfds, 0, sizeof(fd_set));
+        fdzero(readfds, nfds);
     }
 
     if (writefds)
     {
-        memset(writefds, 0, sizeof(fd_set));
+        fdzero(writefds, nfds);
     }
 
     if (exceptfds)
     {
-        memset(exceptfds, 0, sizeof(fd_set));
+        fdzero(exceptfds, nfds);
     }
 
     /* Convert the poll descriptor list back into selects 3 bitsets */

components/lwp/lwp_syscall.c

@@ -27,6 +27,8 @@
 #include <lwp_syscall.h>
 
 #include <dfs_poll.h>
+#include <dfs_select.h>
+
 #if (defined(RT_USING_SAL) && defined(SAL_USING_POSIX))
 #include <sys/socket.h>
 
@@ -235,7 +237,7 @@ const static void* func_table[] =
 
     (void *)sys_gettimeofday,   // 0x0b
     (void *)sys_settimeofday,   // 0x0c
-        
+
     (void *)sys_malloc,         // 0x0d
     (void *)sys_free,           // 0x0e
     (void *)sys_realloc,      //0x0f
@@ -256,6 +258,8 @@ const static void* func_table[] =
     SYSCALL_NET(send),       // 0x1d
     SYSCALL_NET(sendto),     // 0x1e
     SYSCALL_NET(socket),     // 0x1f
+
+    select,                  // 0x20
 };
 
 const void *lwp_get_sys_api(rt_uint32_t number)